Horticultural growing media are currently available in a variety of forms. Media may be produced from natural or synthetic materials. Some growing media are made from loose materials, such as peat and vermiculite. Other growth media are shaped, usually composed of phenolic foam, bonded foam, bonded peat, or wrapped peat, or a fibrous material, such as rock wool. Shaped growing materials are stabilized and held together by incorporation of a synthetic adhesive.
Numerous disadvantages exist when using currently available media; rock wool products, although naturally derived, do not degrade, synthetic fiber or foam growing media consume petroleum in their manufacture and likewise do not degrade, finally, the peat based media are bound together with synthetic polymers. Pollutants, waste, and chemicals can leach into the soil from a synthetic-based medium. Synthetic growing medium is generally not biodegradable and contributes to solid waste at landfills.
However, due to high costs and difficulty in production, there has been little commercial success in natural growth media products. Biodegradability, compostability and biocompatibility are desirable features of a natural growth medium. In addition to these characteristics, a growth medium would ideally be tailored to and produced for specific plant species; size, shape, density, moisture and fluid management characteristics are among these variables.